Painting with rollers as opposed to brushes is virtually universal in situations where broad surfaces need to be coated. Some rollers are made very cheaply with the intent that they be discarded after use, but the better rollers, such as those made with lambs wool, are sufficiently expensive that discarding them is a needless waste.
Of course if the roller is not discarded the problem of cleaning it becomes paramount. The technique used by most amateur painters is to run tap water over the roller continuously until paint ceases to leach out of the roller nap. However, anyone who has done this will testify that the nap of the roller seems to contain an endless supply of paint, and the painter will stand for many minutes, wringing out the nap under the constantly flowing water, until a reasonable clear rinse solution indicates most of the paint has been purged.
More efficient devices have been developed utilizing solutions in containers with rotary cranks which operate the paint roller in the solution against some kind of squeegee bar. However, those that have been patented typically are complicated and would be prohibitively expensive to manufacture and awkward to use, not to mention probably messy. Apparently none of these devices have ever been marketed.
A device which has been successfully marketed and is quite handy is the paint roller spinner. This spinner, in some of its implementations also capable of spinning paint brushes, engages the paint roller from the inside and rotates it rapidly along its longitudinal axis, either under a water faucet or in the open air and is helpful in cleaning the roller. The pair spinner is an integral part of the instant invention.